linux/drivers/hwmon/ltc2992.c

969 lines
24 KiB

hwmon: (ltc2992) Clamp threshold writes to hardware range ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power() do not validate the user-supplied value before converting it to a register value. This can result in: 1. Negative input values wrapping to large positive register values. For power, the negative long is implicitly cast to u64 in mul_u64_u32_div(), producing an incorrect value. For voltage and current, the negative converted value wraps when passed to ltc2992_write_reg() as a u32. 2. Intermediate arithmetic exceeding the range representable in u64 on 64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can exceed U64_MAX when val is a large positive long. In ltc2992_set_current(), (u64)val * r_sense_uohm can overflow similarly. In ltc2992_set_power(), the computed value may not fit in u64. 3. Register values exceeding the hardware field width. Voltage and current threshold registers are 12-bit (stored left-justified in 16 bits), and power threshold registers are 24-bit. Without clamping, bits above the field width are truncated in ltc2992_write_reg(). Fix by clamping negative values to zero, clamping positive values to the rounded hardware-representable maximum (the value returned by the read path for a full-scale register) to prevent intermediate overflow, and clamping the converted register value to the hardware field width before writing. The existing conversion formula and rounding behavior are preserved. In the power write path, cancel the factor of 1000 from both the numerator (r_sense_uohm * 1000) and the denominator (VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms. Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2026-04-16 21:59:30 +00:00
hwmon: (ltc2992) Clamp threshold writes to hardware range ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power() do not validate the user-supplied value before converting it to a register value. This can result in: 1. Negative input values wrapping to large positive register values. For power, the negative long is implicitly cast to u64 in mul_u64_u32_div(), producing an incorrect value. For voltage and current, the negative converted value wraps when passed to ltc2992_write_reg() as a u32. 2. Intermediate arithmetic exceeding the range representable in u64 on 64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can exceed U64_MAX when val is a large positive long. In ltc2992_set_current(), (u64)val * r_sense_uohm can overflow similarly. In ltc2992_set_power(), the computed value may not fit in u64. 3. Register values exceeding the hardware field width. Voltage and current threshold registers are 12-bit (stored left-justified in 16 bits), and power threshold registers are 24-bit. Without clamping, bits above the field width are truncated in ltc2992_write_reg(). Fix by clamping negative values to zero, clamping positive values to the rounded hardware-representable maximum (the value returned by the read path for a full-scale register) to prevent intermediate overflow, and clamping the converted register value to the hardware field width before writing. The existing conversion formula and rounding behavior are preserved. In the power write path, cancel the factor of 1000 from both the numerator (r_sense_uohm * 1000) and the denominator (VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms. Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2026-04-16 21:59:30 +00:00
hwmon: (ltc2992) Clamp threshold writes to hardware range ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power() do not validate the user-supplied value before converting it to a register value. This can result in: 1. Negative input values wrapping to large positive register values. For power, the negative long is implicitly cast to u64 in mul_u64_u32_div(), producing an incorrect value. For voltage and current, the negative converted value wraps when passed to ltc2992_write_reg() as a u32. 2. Intermediate arithmetic exceeding the range representable in u64 on 64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can exceed U64_MAX when val is a large positive long. In ltc2992_set_current(), (u64)val * r_sense_uohm can overflow similarly. In ltc2992_set_power(), the computed value may not fit in u64. 3. Register values exceeding the hardware field width. Voltage and current threshold registers are 12-bit (stored left-justified in 16 bits), and power threshold registers are 24-bit. Without clamping, bits above the field width are truncated in ltc2992_write_reg(). Fix by clamping negative values to zero, clamping positive values to the rounded hardware-representable maximum (the value returned by the read path for a full-scale register) to prevent intermediate overflow, and clamping the converted register value to the hardware field width before writing. The existing conversion formula and rounding behavior are preserved. In the power write path, cancel the factor of 1000 from both the numerator (r_sense_uohm * 1000) and the denominator (VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms. Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2026-04-16 21:59:30 +00:00
hwmon: (ltc2992) Clamp threshold writes to hardware range ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power() do not validate the user-supplied value before converting it to a register value. This can result in: 1. Negative input values wrapping to large positive register values. For power, the negative long is implicitly cast to u64 in mul_u64_u32_div(), producing an incorrect value. For voltage and current, the negative converted value wraps when passed to ltc2992_write_reg() as a u32. 2. Intermediate arithmetic exceeding the range representable in u64 on 64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can exceed U64_MAX when val is a large positive long. In ltc2992_set_current(), (u64)val * r_sense_uohm can overflow similarly. In ltc2992_set_power(), the computed value may not fit in u64. 3. Register values exceeding the hardware field width. Voltage and current threshold registers are 12-bit (stored left-justified in 16 bits), and power threshold registers are 24-bit. Without clamping, bits above the field width are truncated in ltc2992_write_reg(). Fix by clamping negative values to zero, clamping positive values to the rounded hardware-representable maximum (the value returned by the read path for a full-scale register) to prevent intermediate overflow, and clamping the converted register value to the hardware field width before writing. The existing conversion formula and rounding behavior are preserved. In the power write path, cancel the factor of 1000 from both the numerator (r_sense_uohm * 1000) and the denominator (VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms. Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2026-04-16 21:59:30 +00:00
hwmon: (ltc2992) Clamp threshold writes to hardware range ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power() do not validate the user-supplied value before converting it to a register value. This can result in: 1. Negative input values wrapping to large positive register values. For power, the negative long is implicitly cast to u64 in mul_u64_u32_div(), producing an incorrect value. For voltage and current, the negative converted value wraps when passed to ltc2992_write_reg() as a u32. 2. Intermediate arithmetic exceeding the range representable in u64 on 64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can exceed U64_MAX when val is a large positive long. In ltc2992_set_current(), (u64)val * r_sense_uohm can overflow similarly. In ltc2992_set_power(), the computed value may not fit in u64. 3. Register values exceeding the hardware field width. Voltage and current threshold registers are 12-bit (stored left-justified in 16 bits), and power threshold registers are 24-bit. Without clamping, bits above the field width are truncated in ltc2992_write_reg(). Fix by clamping negative values to zero, clamping positive values to the rounded hardware-representable maximum (the value returned by the read path for a full-scale register) to prevent intermediate overflow, and clamping the converted register value to the hardware field width before writing. The existing conversion formula and rounding behavior are preserved. In the power write path, cancel the factor of 1000 from both the numerator (r_sense_uohm * 1000) and the denominator (VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms. Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2026-04-16 21:59:30 +00:00
hwmon: (ltc2992) Clamp threshold writes to hardware range ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power() do not validate the user-supplied value before converting it to a register value. This can result in: 1. Negative input values wrapping to large positive register values. For power, the negative long is implicitly cast to u64 in mul_u64_u32_div(), producing an incorrect value. For voltage and current, the negative converted value wraps when passed to ltc2992_write_reg() as a u32. 2. Intermediate arithmetic exceeding the range representable in u64 on 64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can exceed U64_MAX when val is a large positive long. In ltc2992_set_current(), (u64)val * r_sense_uohm can overflow similarly. In ltc2992_set_power(), the computed value may not fit in u64. 3. Register values exceeding the hardware field width. Voltage and current threshold registers are 12-bit (stored left-justified in 16 bits), and power threshold registers are 24-bit. Without clamping, bits above the field width are truncated in ltc2992_write_reg(). Fix by clamping negative values to zero, clamping positive values to the rounded hardware-representable maximum (the value returned by the read path for a full-scale register) to prevent intermediate overflow, and clamping the converted register value to the hardware field width before writing. The existing conversion formula and rounding behavior are preserved. In the power write path, cancel the factor of 1000 from both the numerator (r_sense_uohm * 1000) and the denominator (VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms. Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2026-04-16 21:59:30 +00:00
hwmon: use simple i2c probe All these drivers have an i2c probe function which doesn't use the "struct i2c_device_id *id" parameter, so they can trivially be converted to the "probe_new" style of probe with a single argument. This is part of an ongoing transition to single-argument i2c probe functions. Old-style probe functions involve a call to i2c_match_id: in drivers/i2c/i2c-core-base.c, /* * When there are no more users of probe(), * rename probe_new to probe. */ if (driver->probe_new) status = driver->probe_new(client); else if (driver->probe) status = driver->probe(client, i2c_match_id(driver->id_table, client)); else status = -EINVAL; Drivers which don't need the second parameter can be declared using probe_new instead, avoiding the call to i2c_match_id. Drivers which do can still be converted to probe_new-style, calling i2c_match_id themselves (as is done currently for of_match_id). This change was done using the following Coccinelle script, and fixed up for whitespace changes: @ rule1 @ identifier fn; identifier client, id; @@ - static int fn(struct i2c_client *client, const struct i2c_device_id *id) + static int fn(struct i2c_client *client) { ...when != id } @ rule2 depends on rule1 @ identifier rule1.fn; identifier driver; @@ struct i2c_driver driver = { - .probe + .probe_new = ( fn | - &fn + fn ) , }; Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20221011143309.3141267-1-steve@sk2.org Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2022-10-11 16:33:08 +02:00